"Kurt Ullman" wrote in message
Why? Epoxy glues are labeled specifically for use as sealants for
plastic gasoline containers. For example:
http://www.pcepoxy.com/pastepoxies/pastesuper.asp


This is why
***Note: PC-Super Epoxy® will not bond to wax paper, Teflon®,
Polyethylene, and some other plastics. There are hundreds of plastics in
thousands of combination. Test a small area when in doubt.

It may work on some tanks of some plastics, but not on very many as
the ones on small engines often are polyethylene or a compound containing
it.